BIOLOGY 1M03 Lecture Notes - Lecture 4: Spalax, Umbilical Cord, Aniridia
8 Feb 2017
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Correlation between geography and patterns of diversity (past vs. present): Large scale: distribution of types of mammals (placental vs marsupial) Genetic basis of selection: candidate gene approaches (darwin"s finches) Traits that have lost their ancestral function in a species but are still retained by that species. Human appendix for digestion, nothing for us now. Eyes of blind mole rat (they"re blind, but have eyes) Human bellybutton is not a vestigial trait because yes it doesn"t as adults, but as embryos we needed the umbilical cord. Homology: is a similarity that exists in species that was inherited from an ancestor. Genetic homology: is a similarity among species in dna sequences, gene content, or other genetic attributes that is due to shared ancestry. Developmental homology: is a similarity among species in embryonic traits that is due to shared ancestry. An identical or almost identical system is used by all known organisms to store sequence of amino acids in proteins in nucleotides.
